Bolt-anchor.



H. W. NEWER.

BOLT ANCHOR.

APPLICATION FILED 1AI-I.20.

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H. W. PLEISTEH.

son ANCHOR.

APPLICATION FILED JN.20. 191?. E $36!, Patnted Nom 2?, MU.,

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HENRY W. PLEISTELR, OF WESTFIELD, NEW JERSEY, ASSIGNOR TG HENRY B. NEWHALL.

BOLTANCHOR.

Patented Nov, 2*?, 191W...

Griginal application iiled September 20, 1916, Serial No. 121,104. Divided and this application led January 20, 191'?. Serial No. 143,425.

To all whom t may concern:

Be it known that I, HENRY WV. PLnisTnR, a. citizen of the United States, residing at Westeld, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Bolt-Anchors, of which the following is a specification, taken in connection with the accompanying drawings.

VVThis application is a4 division of my copending application Ser. No. 121,104 filed Sept. 20, 1916, for improvements in bolt anchors.

My invention relates to bolt anchors.

In the present form of bolt anchors the maximum expansion is approximately at the' extreme inner end of the anchor. In practice this is often a serious detriment in that the screw or other expanding member, having forced the bolt anchor out to its maximum expansion, binds and it is impossible to bring the head of the bolt or screw up flush with the work. This requires that the hole be enlarged entailing` `additional labor and expense, or that a different size bolt anchor be used.

By my invention I overcome this serious objection and give a longer surface of maximum'contact or grip on the exterior of the bolt anchor, thereby giving an i11- creased frictional hold and distributing this maximum grip over a larger area than with the present forms. My invention further permits the screw or bolt to coperate with the bolt anchor with less edort, than in theV present forms.`

My invention further relates to certain details of construction which will be described in the specification and pointed out in the claims. y y Y I have shown in the accompanying drawings an illustrative embodiment of my invention but of course it is to be understood that my invention is not to be confined simply to the form illustrated except as required by the scope of? the appended claims. In these drawings the same reference numeral refers to similar parts yin the severa figures.

Figure lis a vertical longitudinal section through a one-part bolt anchor known as a one part lag shield;

Fig. 2 is a vertical section through the one part shield shown in Fig. 1, thewsup? port and the work supported, the lag screw being in side elevation;

Fig. 3 is a longitudinal vertical section showing the bolt anchor holding work of a different thickness from that shown in Fig. 1;

Fig. 4 is a longitudinal vertical section through a one part bolt anchor, known as a one port lag shield, provided with weakening portions;

Fig. 5 is a vertical section through the one part lag shield shown in Fig. 4, the support, and the work supported, showing the cooperating lag screw in side elevation.

In the illustrative embodiment of my invention, 1 is a one part lag shield having an open side 2 permit-ting the lag screw 3 to engage directly with the inclined surface 4 and the cylindrical surface 5 of the lag shield and also directly with the wall 6 of the hole 7 in the support 8.

I preferably providemy lag shield with lugs 9, 9. The inclined surface 4 merges about at the point 10 with the cylindrical surface 5.

In the form of lag shield now on the market, the bore has an inclined substan tially uniform taper extending from near one end to the other end of the shield. In cooperating with a lagscrew, such as 3, the maximum expansion in the old form is approximately at the end of the old lag shield.

In my present invention the lag shield is provided with an open throat 11 which so far as the expansion is concerned is neutral, in that there is no expansive cooperation between the open throat and the lag screw 3. Not until the las` screw engages the inclined surface 4 does the lag shield begin to expand or positively grip that portion of the wall of the support 8 lying adjacent to it. This expansion continues until the lag screw 3 has reached the point 10 when it will travel along the cylindrical, or semicylindrical, surface 5, with the same expansive power or force that it developed at the point 10 until the end 12 of the lag shield is reached.

The maximum expansion therefore instead of being, as in the old form at the extreme inner end 13 of the lag shield, will be distributed between substantially the points 13 and 14. It is understood of course,

that the -relative length of the inclined sur-` female threads 18, 18 of the lagy shield 1 and bite into that portion of the surface 6 of thehole 7 which is not covered by the lag shield. Y

In Fig. 8 I have illustrated the work 19 of greater thickness held by the same lag screw 3. and lag shield 1. With such work, as well as with work of the thickness of the work 15, the head of the lag screw can be instantly brought up flush against the work without the screw jamming in the lag shield in a position where its head 20 can-A not be brought up1 snugly against the work. 'lhis is due to the fact that the point of maximum expansionis extended over a relatively large portion of the surface of the lag shield so that the end of the screw can be brought anywhere along the cylindrical su-rface A5, or past the end 12 of the lag shield, as may be found necessary, to bring the head 2O flush against the work and at the same time obtain the requisite maxiy mum expansion of the lag shield. In the old form where the expansion is at the endA of the shield, the lag screw would, as previously noted, often jam at that point before its head was brought up flush against the work requiring the removal of the lag shield andthe enlargement of the hole, or theuse. of a different size lag shield.

Preferably the wall of the shell is thin at the point 21 and increases uniformly in thickness to a point, as for example 10, intermediate its extremities, and from that point the thickness of the shell continues with a uniform maximum thickness, to the end; l2.-

l It will. be seen that when the expanding meanscoperates with the axial bore, said bore. is distorted into a substantially tr-ue cylindrical. bore thereby distorting the forwardg exterior cylindrical surface of thebolt anchor into a frustum of a cone, which merges. into the cylindrical exterior,l ofi` the outerend of the bolt anchor.

In some cases to permit the more ready bending. or expansion of the lagv shield, 23, Eigsgl and 5, I; provide it withweakening portions 24, in. any suitablemanner, preferably located adjacent to the point of nearest approach to the axis of ther inclined surfaceV 25.

InV theseI figures, the lag shield 23. is prof vided; with an open throat 26 and with anv inclined surface 25 reaching. its, nearest approach to the axis at the point 27 and then merging into the parallel or semi-cy- 24 is formed by casting valleys 31 which,

as previously noted, for best results, should be located adjacent to the point-'27 of the inclined surface 25,

In this form the lag screw Sicoperatesi with the inclined surface 25 and the semicylindrical surface 28 and also with vthat portion 6 of the wall of thehole 7 in the support 8 which is not covered byv the lag shield 3.. Y Y Y Y t Having thus described thisi-nvention in connection` with an illustrative embodiment thereof, to, the details. 0f which I4 do not desirev toy b@ limited, what is claimed as new and what is desired to secure by Letters Patent is set` forth in the appended claims:

1. A bolt anchor comprising expansible member havin-g an openV side provided with a tapering surface ceasing intmediate its length and then merging into` av surface substantially coaxial with theanchor.

s 2. A bolt anchor comprisingan expansible member having an open side-,provided with a sur-face, said surface inclined` longitudinally to the longitudinal. axisto.;1, point intermediate its ends, thence extending sub.- stantially coaxial with the anchor,` and a rotative member adapted .to engage said Vtaperingsurface and a portion of the surface of the hole in. whichv vthe bolt` anchor is located-. l

8. In a bolt anchor thecombination of an expansible member having.- an open throat and an open Vside provided with. a .taperingv surface ceasing intermediate` its. lengthand witha surface extending substantially coaxial. with the anchor, and a rotative member adapted-.to engage said taperingy and e.0V

axial surfaces and a portion of the` surface of the hole in which the bolt anchor islocated. n a

l. In a bolt anchor the combination` of an expansible member having an openr sideprovided. with. a tapering screwthreaded sur-y face; ceasing` intermediate its length. and merging into a surface substantially- 00,-- axiall with theV bolt anchor, and ai screw adapted to engage, both said tapering and coaxial surfaces-and the surface of-:thehole in1 which the bolt anchor-is located.

5.. In` a` boltV anchor-the combination.-` of an expansiblemember having an4 open side'pro.- vided with a; tapering surface ceasinginter.-

mediate its length.v andy merging intofa cylin drical surface, one ormore lugs, and arotatiye-member adaptedfto engage: both. said tapering andI cylindrical surfaces and the surface of the hole in which the bolt anchor islocated. Y

6. A. bolt anchor1 comprising an expansible member having an open side provided expansible member having an open side and a a weakening portion, said open side provided With a tapering surface for part of its length, and merging into a cylindrical surface substantially coaxial With the rotative expanding member, and a rotative member adapted to engage both said tapering and cylindrical surfaces and the surface of the hole in Which the bolt anchor is located.

HENRY W. PLElSTER. Witnesses M. R. RYAN, A. M. WILLIAMS.

Gopies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patente,

` Washington, D. C. 

